Author Topic: Reduced DPI issues  (Read 177 times)

Taartsel

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Reduced DPI issues
« on: September 20, 2017, 07:52:13 pm »
Hi! So far I couldn't find anyone with this specific problem, so I was hoping someone could help me out. Maybe I'm just missing something, but here's the problem:
I have an image (or several actually) of 300dpi, 3000x3000px large. It's a .tif file. Whenever I check it with Windows image properties or the Linux equivalent of image properties, it says it's indeed 300dpi and 3000x3000px large. But whenever I import it into Scribus, it tells me the image is 72dpi, even though it's placed in a invitation sized (5" x 7" inch) document. When I do a preflight when exporting to PDF it tells me the image is 117dpi (probably because it imported as 72dpi and I resized it significantly smaller in the design).
When I try the same thing in Adobe Indesign (5" x 7" inch, 300dpi document, same image file imported), it loads just fine as a 300dpi image like it was meant to. What is going wrong in this process that results in this loss of dpi? I can't seem to figure it out.

Does anyone have a clue?

Nermander

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Re: Reduced DPI issues
« Reply #1 on: September 20, 2017, 08:09:04 pm »
DPI does not "exist", is computed from the number of pixels and the printed size of the image.

You image is 3000x3000 pixels. It will only become 300 DPI if printed as 10x10 inches.

If you print it at 5x5 inches it will become 600 DPI and if you print it at 20x20 inches it will become 150 DPI.

What puzzles me here is that Scribus reports the image as 117 DPI when it is in a frame that (as far as I understand) is smaller than 10x10 inches (since the document is just 5x7).

Can you explain how you import the image into Scribus? Because the numbers don't look correct, so I suspect you are doing something strange here.

Taartsel

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Re: Reduced DPI issues
« Reply #2 on: September 20, 2017, 08:29:40 pm »
That's what puzzles me too. Placing the image smaller should give it a larger dpi, not a smaller one.
I import the files by drawing an image frame the size I want it and then right-click and choose "Get image...". I pick the image from the folder, but there it starts showing some strange things; instead of 300 dpi (the image's dpi on the original image size of 3000px) it says the image is 72dpi. In fact, it says that about every image, even though the same images are saved as 300dpi files and show up larger than the drawn image frame when placed, making it seem that they indeed should be larger than 300dpi when adjusted to the image frame's size.

mnawij

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Re: Reduced DPI issues
« Reply #3 on: September 22, 2017, 04:32:44 am »
Hello Taartsel, just curious what file type is the import... jpg tif png?

mnawij

Nermander

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Re: Reduced DPI issues
« Reply #4 on: September 23, 2017, 09:08:52 am »

mnawij

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Re: Reduced DPI issues
« Reply #5 on: September 23, 2017, 07:50:02 pm »
I have never seen that with tif files, I know that digital jpg files from cameras and phones are always 72dpi at a large dimension 40" x 32" or such depending on the megapixels of the device.  Unless opened first and resized to the right dpi/resolution and size in a photo editor, all that happens is the photo is scaled down at 72dpi inside of indesign, illustrator, etc... can someone confirm that this happens in scribus, maybe I can if I get a free minute???  I am not sure if this is what is happening or not.  Uploading one of the tif files for me to try and recreate your problem would be the next step if you are amenable to that.

mnawij